A method and apparatus for preventing selection of Deleted (D) members as
an LRU victim during LRU victim selection. During each cache access
targeting the particular congruence class, the deleted cache line is
identified from information in the cache directory. A location of a
deleted cache line is pipelined through the cache architecture during LRU
victim selection. The information is latched and then passed to MRU
vector generation logic. An MRU vector is generated and passed to the MRU
update logic, which is selects/tags the deleted member as a MRU member.
The make MRU operation affects only the lower level LRU state bits
arranged in a tree-based structure state bits so that the make MRU
operation only negates selection of the specific member in the D state,
without affecting LRU victim selection of the other members.